Manually managing iSCSI connections¶

Most iscsi related operations are automaticbut there are situations where manual intervention is necessary. This guide describes how to retrieve iscsi credentials, login into targets, format drives, mount them etc.

Retrieving the drive array’s connection details from the UI¶

Click on on an instance array and go to the DriveArray tabs
Select one of the drive arrays
Click on Show Drives
Scroll down to iSCSI credentials

../_images/managing_drive_arrays3.png

Retriving iscsi access credentials using the CLI¶

Typically drive arrays that are part of the same target as other drives that are mounted in the operating system automatically. However if you need to manually mount a drive use the following:

This is the LUN that you will need to mount:

$ metalcloud-cli drive-array get -id drive-array-45929 -show-credentials
Drive Array #45929 attached to instance array 35517 has the following drives:
+-------+-------------------------------+-----------+-----------+-----------+-------------------------------+--------------------------+--------------------------+-----------------------------------------------------------------------------------------------------+
| ID    | LABEL                         | STATUS    | SIZE (MB) | TYPE      | ATTACHED TO                   | TEMPLATE                 | DETAILS                  | CREDENTIALS                                                                                         |
+-------+-------------------------------+-----------+-----------+-----------+-------------------------------+--------------------------+--------------------------+-----------------------------------------------------------------------------------------------------+
| 71587 | drive-71587                   | active    | 40960     | iscsi_ssd | instance-56008                | CentOS 7.4(#78)          | CentOS  none             | Target: 100.96.0.12 Port:3260 IQN:iqn.2013-01.com.bigstep:storage.dd.6fjo87t.dd LUN ID:33 |
+-------+-------------------------------+-----------+-----------+-----------+-------------------------------+--------------------------+-----------------------

This are the initiator credentials. These should already be configured on the instance but if they are not use the following to retrieve them:

$ metalcloud-cli instance-array get -id workers -show-iscsi-credentials
Instances of instance array workers (#35516) of infrastructure complex-demo (#25524):
+-------+---------------------------+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------+
| ID    | SUBDOMAIN                 | WAN_IP       | DETAILS        | STATUS | ISCSI                                                                                                          |
+-------+---------------------------+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------+
| 56006 | instance-56006.bigstep.io | 84.40.60.226 | M.8.32 (#123)  | active | Initiator IQN: iqn.2019-03.com.bigstep.storage.instance-56006 Username: asdads Password: dd  |
| 56007 | instance-56007.bigstep.io | 84.40.60.227 | M.8.32 (#124)  | active | Initiator IQN: iqn.2019-03.com.bigstep.storage.instance-56007 Username: asd Password: dd  |
+-------+---------------------------+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------+
Total: 2 Instances

Logging into the iSCSI target from Linux (CentOS/Redhat)¶

This process is operating system version but in general lines it requires a user to configure it’s iscsi initiator (the server) and login into the target (the storage).

Install iscsi support
```
yum install iscsi-initiator-utils
```

Set node.startup to automatic.

vi /etc/iscsi/iscsid.conf

[...]
node.startup = automatic
[...]

Start the iSCSI discovery

iscsiadm -m discovery -t st -p 100.96.0.12
iscsiadm -m node

Login the iSCSI target. Notice the .33 at the end of the IQN. That’s the LUN ID from the drive array’s credentials.

iscsiadm -m node --targetname "iqn.2013-01.com.bigstep:storage.dd.6fjo87t.dd.33" --portal "100.96.0.12:3260" --login

Identifying the drive by looking at dmesg
```
$ dmesg
```
Formatting & mounting the drive The drive is now visible in the OS just like any other drive:
```
$ mkfs.ext3 /dev/sdb1
$ mount /dev/sdb1 /mnt
$ ls -l
```

Logging into a drive on Windows using PowerShell¶

Set iSCSI Initiator service to started and automatic

Set-Service msiscsi -startuptype "automatic"
Start-Service msiscsi

Check iSCSI Initiator Configuration Initiator Name

(Get-WmiObject -Namespace root\wmi -Class MSiSCSIInitiator_MethodClass).iSCSINodeName

Set iSCSI Initiator Configuration Initiator Name. Note -NewNodeAddress is retrieved from the CLI by running metalcloud-cli instance-array get -id workers -show-iscsi-credentials

$AddInP = (Get-InitiatorPort)
$AddInP | Select NodeAddress
Set-InitiatorPort -NodeAddress $AddInP.NodeAddress -NewNodeAddress "iqn.2020-03.com.bigstep.storage:instance-0000"

Add a new portal

New-IscsiTargetPortal -TargetPortalAddress "100.96.0.192" -AuthenticationType OneWayCHAP -ChapUsername "ss" -ChapSecret "ss"

Add a new target

$GIT = Get-IscsiTarget | Where-Object {$_.IsConnected -like "False"}

Connect to the new target (disconnect if already connected)

Disconnect-IscsiTarget -NodeAddress $GIT.NodeAddress -Confirm:$false
Connect-IscsiTarget -nodeaddress $GIT.NodeAddress

Make persistent You can skip this step or set the -IsPersistent to false if reconnect not required at reboot
```
Connect-IscsiTarget -nodeaddress $GIT.NodeAddress -IsPersistent $True
```

Connect to the target

Connect-IscsiTarget -nodeaddress $GIT.NodeAddress -IsPersistent $False -AsJob

Prepare and format disk in Powershell¶

To make all attached disks online

Get-Disk | Where-Object IsOffline –Eq $True | Set-Disk –IsOffline $False

To Initialize all raw disks. This will initialize the disks and create new partitions and format the drive without confirmation.

Get-Disk | Where-Object Partitionstyle -eq ‘RAW’ | Initialize-Disk -PartitionStyle GPT -PassThru | New-Partition -AssignDriveLetter -UseMaximumSize | Format-Volume -FileSystem NTFS -Confirm:$false

Disconnect from all iscsi targets in Windows using Powershell Or Just disconnect Offline target¶

To disconnect all connections. You may receive an error if there are files open on the associated drive. This will disconnect without confirmation

$GIT = Get-IscsiTarget | Where-Object {$_.IsConnected -like "True"}
Disconnect-IscsiTarget -NodeAddress $GIT.NodeAddress -Confirm:$false

Or you can use the below. This will disconnect without confirmation

Get-IscsiTarget | Where-Object IsConnected -Eq $True | Disconnect-IscsiTarget -Confirm:$false

Warning, the above two will disconnect ALL iSCSI drives. If your operating system is on iSCSI, it is safer to use the below two commands

Offline disks which are not Boot

Get-Disk | Where-Object IsBoot -Eq $False | Set-Disk -IsOffline $True

Disconnect iSCSI connection of offline disk

Get-Disk | Where-Object -FilterScript {($_.BusType -Eq "iSCSI") -and ($_.IsOffline -Eq $True)} | Get-IscsiSession | Get-IscsiTarget | Disconnect-IscsiTarget -Confirm:$false

Disable indexing on a drive in Powershell¶

To disable indexing on a drive, you must first create a function

function Disable-Indexing{
Param($Drive)
$obj = Get-WmiObject -Class Win32_Volume -Filter "DriveLetter='$Drive'"
$indexing = $obj.IndexingEnabled
if("$indexing" -eq $True){
write-host "Disabling indexing of drive $Drive"
$obj | Set-WmiInstance -Arguments @{IndexingEnabled=$False} | Out-Null
}
}

To save as a function Go to C:\Program Files\WindowsPowerShell\Modules and create a folder called Indexing Save it in C:\Program Files\WindowsPowerShell\Modules\Indexing and save it as Indexing.psm1 as a script

Usage

Disable-Indexing "d:" 
where "d:" is the drive